LONDON  No wonder Manchester United manager Alex Ferguson insists Cristiano Ronaldo would be wrong to play for Real Madrid. The Portuguese star probably would be overshadowed by Lionel Messi.

Ferguson actually believes Ronaldo is at the best club anyway. But the fact that the winger would be compared week by week in the same league as Messi most likely would hurt his chances of proving himself the world's best player.

Messi is at the center of a tug of war between Barcelona and Argentina's team for the Olympics. He played brilliantly for his club in warmup games in Scotland.

After scoring and mesmerizing the Hibernian defense in Barca's 6-0 victory in Edinburgh on Thursday, he went on as a second-half substitute against Dundee United on Saturday and collected a hat trick in a 5-1 victory at Dundee United.

Weaving inside and outside defenders, Messi had them going in different directions and chasing his shadow. By the time they realized where he had gone, the ball was in the back of the net.

"He was fantastic to watch and what a difference he made to the game," said Dundee United manager Craig Levein, who played for Scotland at the 1990 World Cup. "It's not often that we lose 5-1 and I'm smiling watching the opposition playing football. He was just a real delight to watch."

Although these aren't the toughest opponents Messi will face next season, the 21-year-old Argentine showed he has the skills and the goal-scoring ability to dwarf even the likes of Ronaldo.

Ronaldo relies more on his speed and is better in the air. Messi has the edge in dribbling in tight situations. He draws defenders toward him and out of position, then leaves them trailing with short bursts of fancy footwork, either scoring himself or setting up others.

Ronaldo certainly outshone Messi last season. He scored 42 goals for United and helped the Red Devils win the Premier League and Champions League, ousting Barcelona in the semifinals. But he missed a third-minute penalty kick in the first leg at Camp Nou and, in those two games, Messi looked the better player.

Messi has also been hampered by injuries.

In 2006, he tore muscle fibers in his right thigh in a Champions League game against Chelsea and missed the rest of the season, including Barcelona's victory over Arsenal in the final. Last year, he had two long spells on the sidelines with leg injuries. Without him, Barca finished well behind Madrid in the Spanish title race.

Barcelona's new coach, Pep Guardiola, prefers to take the heat off Messi and stresses the importance of team play.

"I understand that everybody thinks that Messi is different, of course he is different, but I have to treat him the same as the others," said Guardiola, who replaced Frank Rijkaard at the end of last season.

"I don't understand football only with one player. I understand football as a result of the work of the group. For him to do the things he does, he needs someone to bring the ball to him, to create opportunities to score."

Now Messi is fit and appears to be getting back to his best form while Ronaldo has an ankle injury that will sideline him until early October.

While Messi doesn't yet know whether he will go to the Olympics, Ronaldo doesn't know which team he'll be playing for next season.

Ronaldo says he wants to move to Madrid, and the Spanish club is eager to get him for what would certainly be a world-record transfer fee. But United is holding him to his contract, which still has almost four years to run.

Messi is unlikely to be leaving Barcelona. His value to the club and its bid to regain both the Spanish league and Champions League titles are behind its reluctance to let him go to China.

After Messi was placed on Argentina's Olympic squad, Barcelona said it had not given permission for him to go. FIFA, which has instructed clubs to release the players for China, has appointed a judge who is to rule Tuesday. Several German clubs have also refused to release players for the Olympic tournament, which begins in 10 days.

Messi is vital to Argentina and Barcelona.

Guardiola wants Messi when his team plays in the qualifying round of the Champions League, which coincides with Olympic soccer. But Argentina is defending the Olympic title and is offering Messi the chance to win a gold medal.

If the judge's decision goes the way of the Olympic teams, Messi could be one step ahead of Ronaldo. While the Portuguese star sits at home wondering where he'll play next season, Messi could go into the season an Olympic champion.

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